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2 years ago

9

If a = 4 and b = 2, what is the value of the following expression?

2 answers:

romanna [79]2 years ago

4 0

The correct answer is D. 30.

Nadya [2.5K]2 years ago

3 0

Answer:

D) 30

Step-by-step explanation:

3(a + 4b)-6 = 3 ( 4 + 4*2) - 6

= 3( 4+8 ) - 6

= 3*12 - 6

= 36 - 6 =30

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How much do you need to subtract from 41/6 to get 6

Svetllana [295]

Well 41 divided by 6 is 6.8333333333333 so you just need to subtract .833333333333

I hope this answered your question

3 0

2 years ago

Factorise fully <br>-14x - 8<br><br>ease do quick, will mark brainiest!

OleMash [197]

Answer:

-2( 7x+4)

Step-by-step explanation:

-14x - 8

Factor out -2

-2*7x -2*4

-2( 7x+4)

5 0

3 years ago

Read 2 more answers

There are 234 pieces of candy in 9 bags of candy. If there are the same amount of pieces of candy in each bag, how many total pi

spin [16.1K]

Answer:

130 pieces of candy in 5 bags

Step-by-step explanation:

234/9 equals 26, that means there would be 26 pieces of candy in 9 bags, therefore 26x5 equals 130, and just to make sure, divide 130/26 to check if its wrong, but it should be 130. :) hope this helps you out!

8 0

2 years ago

Given the quadratic function : f(x)=x^24x-12<br> Find the vertex.<br> Can you show the steps?!?

vlada-n [284]

$\bf \textit{vertex of a vertical parabola, using coefficients}
\\\\
\begin{array}{llcccl}
\stackrel{f(x)}{y} = & 1x^2& +4x& -12\\
&\uparrow &\uparrow &\uparrow \\
&a&b&c
\end{array}
\qquad 
\left(-\cfrac{ b}{2 a}\quad ,\quad c-\cfrac{ b^2}{4 a}\right)
\\\\\\
\left(-\cfrac{4}{2(1)}~~,~~-12-\cfrac{4^2}{4(1)} \right)\implies (-2~~,~~-12-4)\implies (-2~~,~~-16)$

6 0

2 years ago

Let the following sample of 8 observations be drawn from a normal population with unknown mean and standard deviation:

Vikentia [17]

Answer:

a

$\= x = 18.5$ , $\sigma = 5.15$

b

$15.505 < \mu < 21.495$

c

$14.93 < \mu < 22.069$

Step-by-step explanation:

From the question we are are told that

The sample data is 21, 14, 13, 24, 17, 22, 25, 12

The sample size is n = 8

Generally the ample mean is evaluated as

$\= x = \frac{\sum x }{n}$

$\= x = \frac{ 21 + 14 + 13 + 24 + 17 + 22+ 25 + 12 }{8}$

$\= x = 18.5$

Generally the standard deviation is mathematically evaluated as

$\sigma = \sqrt{\frac{\sum (x- \=x )^2}{n}}$

$\sigma = \sqrt{\frac{\sum ((21 - 18.5)^2 + (14-18.5)^2+ (13-18.5)^2+ (24-18.5)^2+ (17-18.5)^2+ (22-18.5)^2+ (25-18.5)^2+ (12 -18.5)^2 )}{8}}$

$\sigma = 5.15$

considering part b

Given that the confidence level is 90% then the significance level is evaluated as

$\alpha = 100-90$

$\alpha = 10\%$

$\alpha = 0.10$

Next we obtain the critical value of $\frac{ \alpha }{2}$ from the normal distribution table the value is

$Z_{\frac{ \alpha }{2} } = 1.645$

The margin of error is mathematically represented as

$E = Z_{\frac{ \alpha }{2} } * \frac{\sigma }{\sqrt{n} }$

=> $E =1.645 * \frac{5.15 }{\sqrt{8} }$

=> $E = 2.995$

The 90% confidence interval is evaluated as

$\= x - E < \mu < \= x + E$

substituting values

$18.5 - 2.995 < \mu < 18.5 + 2.995$

$15.505 < \mu < 21.495$

considering part c

Given that the confidence level is 95% then the significance level is evaluated as

$\alpha = 100-95$

$\alpha = 5\%$

$\alpha = 0.05$

Next we obtain the critical value of $\frac{ \alpha }{2}$ from the normal distribution table the value is

$Z_{\frac{ \alpha }{2} } = 1.96$

The margin of error is mathematically represented as

$E = Z_{\frac{ \alpha }{2} } * \frac{\sigma }{\sqrt{n} }$

=> $E =1.96 * \frac{5.15 }{\sqrt{8} }$

=> $E = 3.569$

The 95% confidence interval is evaluated as

$\= x - E < \mu < \= x + E$

substituting values

$18.5 - 3.569 < \mu < 18.5 + 3.569$

$14.93 < \mu < 22.069$

8 0

2 years ago